The present invention relates to an extendable working boom mounted on a prime mover platform (a support vehicle) that has telescoping boom sections that can elongate to a substantial height, and which have hydraulically operated attachments at an outer end to which hydraulic fluid under pressure must be delivered. The boom has a single operating hydraulic cylinder operable to extend and retract the boom. The boom includes a hydraulic hose and line carrier formed as a cartridge or subassembly that slips into the boom and can be removed as a subassembly unit for service, such as replacement of connections, checking for leaks and the like.
Extendable booms have been made in the past, using a single hydraulic cylinder to extend and retract the boom. However, the assembly of the hydraulic hoses and lines necessary to carry hydraulic fluid under pressure to the outer end of the extendable boom have generally involved complex arrangements with line connections in the interior of the boom tubes, and the consequent need for disassembly of the boom in order to service the hydraulics. Usually the connections that may cause problems are on the interior of one of the boom sections, so difficult procedures have to be followed to remove the hoses and lines that are used.